GWD-6-3

叮叮当当

Q3:

If a committee of 3 people is to be selected from among 5 married couples so that the committee does not include two people who are married to each other, how many such committees are possible?

A. 20

B. 40

C. 50

D. 80

E. 120

怎么也算不出是80

daoying

C（3，10）-C（1，5）C（1，8）=120-40=80